Please do NOT go buy any more of them for $5 ...or even $1. It is definitely a 20th-century Imitation of a Gardner minie-ball. Battlefield tourist souvenir shops have been selling these modern-made Imitation Gardners for decades.
The McKee-&-Mason book on civil war bullets ("Civil War Projectiles II: Small Arms & Field Artillery") contains a very serious error -- in actual fact, the Gardner minie-ball did not have a lead-cup insert in its base. Unfortunately, although that book has been reprinted many times, the incorect information about Gardner "insert base" minies has never been removed or corrected.
The McKee-&-Mason book shows one of the 20th-century Imitations, as bullet #294, mistakenly calling it a "Gardner without insert." Please note that it is in non-excavated condition. The book was originally written in the late-1960s, and at that time the authors did not know this minie is an Imitation. Please note that the one shown in the book is in non-excavated condition. That is because (being a 20th-century Imitation) the authors had never seen an excavated one, and the book's photo of it was made in the late-1960s, before fakers had figured out how to put false "dug lead" patina on Repro bullets.
The actual form of the civil war Gardner minie-ball was cast in a special mold, and then "crimped" in Mr. Gardner's patented catridge-assembly machine. That process was too complicated for the souvenir-makers to inexpensively reproduce, so they made the 20th-century Imitations with a simpler base. (By the way, it is correctly called an Imitation rather than a Reproduction, because Reproduction technically means an accurate copy of an Original.
Anybody here who has doubts about the accuracy of any of the information I've given you in this post can ask about it at the Civil War Projectiles forum, at the Bullet-&-Shell website.
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